Android ListView Adapter的getItemViewType和getViewTypeCount多种布局

《Android ListView Adapter的getItemViewType和getViewTypeCount多种布局》

在Android的ListView中，如果在一个ListView中要实现多种样式的ListView布局样式，则需要在ListView的适配器Adapter中用到：getItemViewType()和getViewTypeCount()。getViewTypeCount()告诉ListView需要加载多少种类型的Item View，getItemViewType()则告诉ListView在某一位置（position）的Item View样式是什么。
现给出一个示例加以，说明，本例简单的以字母A、B、C。。。作为数据分组，然后每个字母下有五个数据。

如图：

全部代码：

package zhangphil.listview;import java.util.ArrayList;import java.util.HashMap;import android.app.ListActivity;import android.content.Context;import android.graphics.Color;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ListView;import android.widget.TextView;public class MainActivity extends ListActivity {// item view的类型总数。private final int VIEW_TYPE_COUNT = 2;private final String DATA = "data";private final String TYPE = "type";private final int GROUP = -2;private final int ITEM = -3;private ArrayList<HashMap<String, Object>> items = null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);ListView listView = this.getListView();BaseAdapter adapter = new MyBaseAdapter();items = new ArrayList<HashMap<String, Object>>();listView.setAdapter(adapter);// 假设我们演示以A,B,C,,,这样的字符串作为分组的标签。// 每一组装载5个子数据。String[] groups = { "A", "B", "C", "D", "E", "F" };int count = 0;for (int i = 0; i < groups.length; i++) {HashMap<String, Object> group_map = new HashMap<String, Object>();group_map.put(TYPE, GROUP);group_map.put(DATA, groups[i]);items.add(group_map);for (int j = 0; j < 5; j++) {HashMap<String, Object> data_map = new HashMap<String, Object>();data_map.put(TYPE, ITEM);data_map.put(DATA, "数据:" + (count++));items.add(data_map);}}}private class MyBaseAdapter extends BaseAdapter {private LayoutInflater inflater = null;public MyBaseAdapter() {inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);}@Overridepublic int getCount() {return items.size();}@Overridepublic Object getItem(int position) {HashMap<String, Object> map = items.get(position);return map.get(DATA);}// 返回的id可以自己定制。@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {int type = getItemViewType(position);// 根据不同的view type加载不同的布局文件。switch (type) {case GROUP:convertView = inflater.inflate(android.R.layout.simple_list_item_2, null);TextView tv1 = (TextView) convertView.findViewById(android.R.id.text1);tv1.setText("分组");tv1.setBackgroundColor(Color.RED);TextView tv2 = (TextView) convertView.findViewById(android.R.id.text2);tv2.setText(getItem(position) + "");tv2.setBackgroundColor(Color.GRAY);break;case ITEM:convertView = inflater.inflate(android.R.layout.simple_list_item_1, null);TextView tv = (TextView) convertView.findViewById(android.R.id.text1);tv.setText(getItem(position) + "");break;}return convertView;}// 解析view type。// view type值是我们事先埋入到items数据集中的字段值。// 注意!此处返回的值不要大于getViewTypeCount()的返回值。@Overridepublic int getItemViewType(int position) {HashMap<String, Object> map = items.get(position);return (Integer) map.get(TYPE);}// 在本例中共计有2个不同类型的view// android.R.layout.simple_list_item_1 和// android.R.layout.simple_list_item_1.@Overridepublic int getViewTypeCount() {return VIEW_TYPE_COUNT;}}}

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